Ahlström, Christer

Almqvist, Sverker

Yahya, Mohammad-Reza

Swedish National Road and Transport Research Institute.

2009 (Swedish)Report (Other academic)Alternative title

Evaluation of local ITS solutions in urban areas (English)

Abstract [sv]

This study investigates the acceptance and effect of variable message signs (VMS). Two different systems were evaluated: one where a speed limit sign was combined with a message to slow down and another where a speed limit sign was combined with flashing lights. Both VMS were activated (lit up) if the passing vehicle was driving too fast as it approached the speed limit sign. The aim of the study was to evaluate if the use of a variable speed limit sign gave rise to lower speeds. The same approach was used in order to evaluate the effect of an additional message system or flashing lights. The investigation was conducted in two Swedish villages, Grästorp and Färgelanda, at road sections where the speed limit was momentarily reduced to 50 km/h. In both locations, the use of a variable speed limit sign resulted in speed reduction (mean and 85 percentiles) amongst the drivers. This means that the majority of the drivers, including those that drove much too fast, reduced their speed owing to the VMS. However, no further speed reductions were found when combining the variable speed limit signs with either a message system or flashing lights. Interviews with the drivers revealed that they believed that both VMS systems would increase traffic safety by reducing the speeds. They also stated that variable speed limit sign was enough to increase their awareness of the current speed limit and that no additional message systems or the blinking lights were necessary.